The specification of JP-A-5-262765 and the specification of JP-A-5-25165 disclose some benzofuran derivatives, the specification of JP-A-63-156787 discloses some benzopyran derivatives and benzofuran derivatives, and the specification of European Patent 626962 discloses benzothiophene derivatives and benzofuran derivatives, as they are useful as active ingredients for herbicides.
Herbicides to be used for useful crop plants, are desired to be agents which can be applied to soil or foliage and provide adequate herbicidal effects at low doses and which exhibit selectivity between crop plants and weeds. However, the herbicidal effects and the selectivity between crop plants and weeds, are influenced by the nature of soil, and phytotoxicity may sometimes be brought about to crop plants after the application, irrespective of soil treatment. From such a viewpoint, the compound disclosed in the above literatures can not necessarily be said to be satisfactory.
Under these circumstances, the present inventors have studied the herbicidal effects and the selectivity between crop plants and weeds and as a result, have found that novel benzofuran-7-yl uracil derivatives have excellent herbicidal effects and selectivity between crop plants and weeds, and have accomplished the present invention.